다단 수직형 식물공장 온실에서 순환팬 성능 및 미기후 비균일성의 평가

초록

Multi-layer vertical farming greenhouses have been increasingly adopted to enhance land-use efficiency and enable year-round crop production. However, dense cultivation racks and crop canopies restrict air movement, potentially leading to spatially non-uniform microclimatic conditions. These non-uniform conditions can lead to localized heat and moisture accumulation, reducing the efficiency of environmental control and resulting in non-uniform crop growth. This study experimentally evaluated fan performance and the non-uniformity of the microclimate in a commercial-scale multi-layer vertical farming greenhouse with 34 cultivation racks and above- and below-mounted circulation fans. Field measurements of fan outlet velocity, air temperature, relative humidity (RH), greenhouse air velocity, and a fan-on/off comparison under fully open window conditions were conducted. The results showed substantial variability in the 10 above-mounted fan outlet velocities (3.23－5.00 m/s), lower outlet velocities observed at 90° turning locations, indicating an imbalanced distribution along the circulation path. The four below-mounted fans showed more consistent outlet velocities (3.43－4.57 m/s), but their spatial coverage was limited because only four were installed across 34 cultivation racks. Indoor air temperature and RH measured at 1.5 m height showed moderate spatial non-uniformity, with coefficients of variation of 6.52% and 7.73%, respectively. Central regions consistently exhibited higher temperatures and lower RH. Greenhouse air velocity measured at sensor locations ranged from 0.08 to 0.21 m/s, indicating spatial variation in local airflow magnitude. Under the tested full-open window condition, fan operation was associated with a slight decrease in mean temperature and small reductions in the spatial variability of temperature and RH, suggesting a modest improvement in internal mixing rather than a substantial homogenization. These results provide field-based experimental data essential for future CFD-based analysis and the improvement of environmental control strategies in a multi-layer vertical farming greenhouse.

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